Collaborative Research: Bacterial Flagellar Forests: Designing a Biomaterial for Bio-Enabled Sensing and Actuation

材料研究部的生物材料项目资助德雷塞尔大学和内华达大学里诺分校的研究人员合作，研究细菌鞭毛作为一种具有传感和驱动能力的活性生物材料的组成部分。该合作项目由化学、生物工程、环境和运输系统部门的纳米生物传感项目共同资助。细菌鞭毛是由鞭毛蛋白亚基组成的螺旋自组装结构。多态转化是鞭毛的一个关键特性，它取决于外部刺激，包括温度、离子强度、pH、光强迫，以及特定配体的浓度。但诱导转变所需的具体刺激水平尚未得到很好的确定。提出的工作的目标是创建一个鞭毛森林组成的鞭毛阵列系在一个底物。为了响应外部刺激，鞭毛的多态转化与集体鞭毛动力学相结合，将使鞭毛森林能够感知和自主地响应环境。为了实现这一目标，研究人员将：(1)通过将鞭毛聚集成有序的阵列，将其与由外部旋转磁场驱动的基板上的磁性马达相连，从而形成鞭毛森林；(2)描述单个鞭毛对热、化学、机械和光学环境刺激的响应；(3)了解单个鞭毛如何相互作用以产生鞭毛森林生物材料的集体反应。这个合作项目的更广泛的科学影响是发展对生物系统中宏观尺度自主行为的理解，这种行为是由纳米尺度上的电荷和质量传输控制的，而纳米尺度上的电荷和质量传输又是由大量聚合生物分子的动态响应控制的。该项目的教育目标是有效地向更年轻和更广泛的受众传播前沿研究，并激励他们朝着获得STEM领域学位的目标前进。在工程系统中使用生物纳米材料是理解生物世界如何在纳米尺度上进化的关键一步，也是科学家和工程师如何利用现代组装和合成技术改进自然的关键一步。“智能”系统的设计可以利用材料，这些材料可以对周围环境的变化做出自主反应。此外，这项工作还包括对研究生和本科生的广泛培训，为他们在生物学和工程方面的综合背景下从事学术界和工业界的职业做好准备。在整个项目中，pi将继续招募和指导代表性不足的群体在STEM领域工作。这项研究将通过强有力的外联努力向公众传播。在德雷克塞尔大学（Drexel University）， INSPIRE学院将为高中教师和学生带来尖端的生物材料和生物制造技术。在内华达大学里诺分校，“像微生物一样移动”项目将通过学校的“工程师日”、“暑期工程营”和“移动工程教育实验室”外展项目，为K-12学生和公众带来这项研究。此外，将利用YouTube等网络和社交媒体来传播科学发现，并使科学对K-12学生、教师和普通公众更具吸引力。

The Biomaterials program in the Division of Materials Research funds the collaborative efforts of researchers at Drexel University and University of Nevada Reno to study bacterial flagella as a component of an active biomaterial that are capable of sensing and actuation. This collaborative project is cofunded by the Nano-Biosensing program in the Division of Chemical, Bioengineering, Environmental, and Transport Systems. Bacterial flagella are helical self-assembled structures composed of flagellin subunits. Polymorphic transformations, a key property of flagella, depend on external stimuli including temperature, ionic strength, pH, optical forcing, and possibly by concentration of specific ligands. But the specific levels of stimuli needed to induce transformations have not been well-determined. The goal of the proposed work is to create a flagellar forest consisting of an array of flagella tethered to a substrate. In response to external stimuli, flagellar polymorphic transformations coupled to collective flagellar dynamics will enable the flagellar forest to sense and actuate autonomously in response to the environment. To accomplish the goal, the researchers will: (1) create flagellar forests by gathering filaments into ordered arrays tethered to magnetic motors on a substrate which are actuated by an external rotating magnetic field en masse; (2) characterize the response of individual flagella to thermal, chemical, mechanical, and optical environmental stimuli; and (3) understand how individual flagella interact to create the collective response of the flagellar forest biomaterial. The broader scientific impact of this collaborative project is in developing an understanding how macroscale autonomic behavior in biological systems that is controlled by charge and mass transport at the nanoscale, which, in turn, is controlled by the dynamic response of a vast array of polymeric biomolecules. The educational goal of this project is to effectively communicate cutting-edge research to younger and broader audiences and inspire them toward the goal of obtaining a degree in STEM fields.The use of biological nanomaterials in an engineered system presents a critical step toward understanding how the biological world has evolved at the nanoscale, as well as how scientists and engineers can improve upon nature using modern assembly and synthesis techniques. The design of "smart" systems can take advantage of materials which can respond autonomously to changes in their surroundings. In addition, the work includes an extensive training component for graduate and undergraduate students, preparing them for careers in academia and industry with a comprehensive background in biology and engineering. Throughout the project, the PIs will continue to recruit and mentor underrepresented groups to work in STEM fields. The research will be communicated to the public through strong outreach efforts. At Drexel University, the INSPIRE academy will bring cutting-edge bionanomaterials and biomanufacturing to high school teachers and students. At the University of Nevada, Reno, the "Move Like a Microbe" program will bring this research to life for K-12 students and the public through University's "Engineer's Day", "Summer Engineering Camp", and "Mobile Engineering Education Lab" outreach programs. Additionally, web-based and social media outlets such as YouTube will be utilized to disseminate the scientific discoveries, and to make science more appealing to K-12 students, teachers and the general public.